Tiny 16-Bit ADC Integrates 2ppm/ºC Reference for Space-Constrained Sensor Applications

Linear Technology has introduced the LTC2460 and the LTC2462, a pair of 16-bit delta sigma ADCs that integrate a precision reference in a tiny 3mm x 3mm DFN package. 

The integrated reference (2ppm/°C Typ, 10ppm/°C Max) allows precise measurements and alleviates the need for an external reference, a key benefit for space-constrained applications. Both ADCs guarantee 16-bit no missing code resolution.

This makes the LTC2460 and LTC2462 a complete solution for remote sensor battery-powered applications and industrial sensors monitoring temperature or pressure.

Operating from a single 2.7V to 5.5V supply, these ADCs are designed to measure single-ended (LTC2460) or differential (LTC2462) sensors via an SPI serial interface. With its internal 1.25V reference, the LTC2460 can measure a single-ended input from 0V to 1.25V, while the LTC2462 is capable of measuring a differential input up to ±1.25V.

The versatile LTC2460/LTC2462 achieve excellent 16-bit DC performance of 1LSB (Typ) integral nonlinearity error, 2.2uVRMS transition noise and 0.25% gain error (max). These ADCs have an internal oscillator, another space-saving feature. They operate up to 60 conversions per second, making it easy to measure temperature, pressure, voltage, or other low-frequency sensor signals.

The LTC2460/LTC2462 draw 2.5mA (max) supply current at the 60Hz maximum sample rate with the internal reference active. After each conversion, the ADC enters a shutdown mode, reducing supply current to less than 1.5mA (max). 

Supply current can be further reduced to less than 2uA (max) in sleep mode. The LTC2460/LTC2462 also incorporate a proprietary input sampling network that reduces the dynamic input current to less than 50nA, making possible a wide range of external input filter and protection circuits.

The LTC2460 and LTC2462 join a family that includes the previously released LTC2450 (single-ended input, VCC used as the reference) and LTC2452 (differential input, external reference required). The LTC2450/LTC2452 ADCs should be used for applications that need to measure input signals greater than 1.25V.

The LTC2460 and LTC2462 are each offered in 12-pin ultra-tiny 3mm x 3mm DFN and MSOP packages. They are available today in both commercial and industrial temperature grade versions. Pricing begins at $1.65 each in 1,000-piece quantities. 

For more information, visit www.linear.com.

Summary of Features of the LTC2460/LTC2462:

• 16-Bit Resolution, No Missing Codes
• Internal Reference, (10ppm/°C max)
• Single-Ended (LTC2460) or Differential (LTC2462) Input
• 2LSB Offset Error
• 0.01% Gain Error
• 60 Conversions Per Second
• Single Conversion Settling Time for Multiplexed Applications
• Single-Cycle Operation with Auto Shutdown:
       o 1.5mA (typ) Supply Current
       o 2uA (max) Sleep Current
• Internal Oscillator - No External Components Required
• SPI Interface
• Tiny 12-Lead 3mm × 3mm DFN & MSOP Packages